test_runner: print coverage and diagnostic info with dot reporter

When using the dot reporter with coverage enabled, coverage threshold
failures and coverage reports were not printed, only an exit code was
returned. This made it impossible to know why the test run failed.

This change adds handling for test:diagnostic and test:coverage events
to the dot reporter, matching the behavior of the spec reporter.

Fixes: #60884

Author: mag123c

lib/internal/test_runner/reporter/dot.js

@@ -4,12 +4,19 @@ const {
   MathMax,
 } = primordials;
 const colors = require('internal/util/colors');
-const { formatTestReport } = require('internal/test_runner/reporter/utils');
+const { getCoverageReport } = require('internal/test_runner/utils');
+const {
+  formatTestReport,
+  reporterColorMap,
+  reporterUnicodeSymbolMap,
+} = require('internal/test_runner/reporter/utils');
 
 module.exports = async function* dot(source) {
   let count = 0;
   let columns = getLineLength();
   const failedTests = [];
+  const diagnostics = [];
+  let coverage;
   for await (const { type, data } of source) {
     if (type === 'test:pass') {
       yield `${colors.green}.${colors.reset}`;
@@ -25,8 +32,24 @@ module.exports = async function* dot(source) {
       columns = getLineLength();
       count = 0;
     }
+    if (type === 'test:diagnostic' && data.level === 'error') {
+      ArrayPrototypePush(diagnostics, data);
+    }
+    if (type === 'test:coverage') {
+      coverage = data;
+    }
   }
   yield '\n';
+  if (diagnostics.length > 0) {
+    for (const diagnostic of diagnostics) {
+      const color = reporterColorMap[diagnostic.level] || reporterColorMap['test:diagnostic'];
+      yield `${color}${reporterUnicodeSymbolMap['test:diagnostic']}${diagnostic.message}${colors.white}\n`;
+    }
+    if (coverage) {
+      yield getCoverageReport('', coverage.summary,
+                              reporterUnicodeSymbolMap['test:coverage'], colors.blue, true);
+    }
+  }
   if (failedTests.length > 0) {
     yield `\n${colors.red}Failed tests:${colors.white}\n\n`;
     for (const test of failedTests) {